Volume 33,Issue 8,2010 Table of Contents

1 Topology optimization for constrained layerdamping material in structures using ESO method

LI Yinong , XIE Ronglu , WNG Yi , ZHENG Ling

2010, 33(8):1-6. DOI: 10.11835/j.issn.1000-582X.2010.08.001

[Abstract](2609) [HTML](0) [PDF 2.24 M](1291)

Abstract:
Topology optimization for constrained damping material in structures is investigated in order to suppress structural vibration through the optimal placement of constrained damping material in structure. A mathematical model to describe the topology optimization problem is established. In the topology optimization approach, structural modal damping ratio is designed as objection function, while constrained damping material consumption is considered as constraint condition. The sensitivity of modal damping ratio to the place is analyzed. An evolutionary criterion for placement of constrained damping material in a structure is presented. The formula of sensitivity is derived and used to determine the optimized placement of constrained damping material in structure. The topology optimization problem is further solved by evolutionary structural optimization (ESO) method. The numerical examples are given. The results show that a stable and dramatic increase of the modal damping ratio during the course of iterations can be observed. Therefore, an optimal layout of constrained damping material in structure is obtained. The comparison of amplitude frequency characteristics with the optimal and fully covered layout validates the effectiveness of proposed topology optimized approach.

2 Design of nondestructive examination system for bridge cables surface defect

GUO Yongcai , LI Zhe , GO Chao

2010, 33(8):7-11. DOI: 10.11835/j.issn.1000-582X.2010.08.002

[Abstract](2373) [HTML](0) [PDF 1.58 M](1072)

Abstract:
Aiming at the drawbacks of the current detecting methods, a nondestructive examination system design for bridge cables based on high speed digital signal processors chip DM642 is presented, and the hardware platform of the system is built. This examination system mainly consists of four parts: the image defaults acquisition part, DM642 hardware platform, creeping part and defaults locating equipment. The designed system is tested on the hardware platform based on digital image processing algorithm. The experimental results show that the detecting system has the advantages of high stability and reliability, realtime, mass storage, and nondestructive examination, etc. This system uses high technology and has significant meaning on detecting the current bridge cables health, furthermore, this method can be used in other examination fields.

3 Dualmode ACDCAC converter for contactless power transfer system

SU Yugang , WNG Xiaofei , TANG Chunsen , WANG Zhihui , SUN Yue

2010, 33(8):12-16. DOI: 10.11835/j.issn.1000-582X.2010.08.003

[Abstract](2287) [HTML](0) [PDF 2.80 M](1203)

Abstract:
A new type ACDCAC converter which can work in Buck or Boost mode is proposed in order to overcome the deficiencies of the primary circuit of the traditional contactless power transfer system. Through switching this two modes and turning the duty cycles of the switches, not only the resonant current amplitude of the primary resonant current can be controlled to be constant against a wide range variation of input voltage, but also the problems, such as surge current, high cost, complex control etc., caused by the DC filter and DC/DC converter in a traditional CPT system are effectively eliminated. The topology and operation principle of the proposed converter have been analyzed. The corresponding control strategy has been presented and verified by simulation results.

4 Novel strategy for subcarrier and power allocation in OFDMbased cognitive radio networks

TANG Lun , ZENG Xiaoping , CHEN Qianbin , WNG Huan

2010, 33(8):17-22. DOI: 10.11835/j.issn.1000-582X.2010.08.004

[Abstract](2389) [HTML](0) [PDF 2.46 M](1121)

Abstract:
In order to limit the interference caused by cognitive user within the range that primary users can tolerate. The mathematical optimization problem is formulated maximizing cognitive user’s capacity under the interference constraint at the primary receiver．When the signaltonoise ratio of primary user changes according to the communication environment, the cognitive user can adaptively adjust its transmission power according to the interference control factor η. The optimal so1ution to the problem is obtained by utilizing the Lagrange method．A subcarrier and power allocation scheme are proposedamong multiple cognitive users, which is the performance tradeoff between fairness and system capacity. Simulation results show that the proposed scheme can efficiently guarantee the fairness of cognitive users and the capacity performance is close to the optimum.

5 Multiscale and multiorientation features for image denoising

CHEN Jianjun , TIAN Fengchun , QIU Yu , LI Xinli

2010, 33(8):23-28. DOI: 10.11835/j.issn.1000-582X.2010.08.005

[Abstract](2221) [HTML](0) [PDF 2.07 M](1121)

Abstract:
An adaptive algorithm for image denoising is proposed based on the multiscale and multiorientation features. The coefficients in different scales and different directions are obtained by image decomposition using the nonsubsampled contourlet transform. Then thresholds functions are adaptively set with these coefficients. The texture of the image information is introduced by using the mean of decomposition scale and the energy of regional. The greater the energy, the more information of the texture while the same decomposition scales, the smaller the threshold is set. On the contrary, the greater the threshold is set. After the denoising and then reconstruction of these coefficients, image denoising is implemented. Compare to the wavelet transform threshold and contourlet transform threshold, the nonsubsampled contourlet transform pick up the image detail better and improve the quality of the image.

6 Embedded terminal receiving capability matching in multimedia file transmission

WANG Haiwei , NI Hong , SUN Peng , ZHU Xiaoyong

2010, 33(8):29-35. DOI: 10.11835/j.issn.1000-582X.2010.08.006

[Abstract](2487) [HTML](0) [PDF 2.32 M](1247)

Abstract:
A novel transport protocol for largescaled multimedia file  EMFTP (Embedded Multimedia File Transfer Protocol) is proposed to match the receiving capability of embedded terminal with sufficient network bandwidth. EMFTP is an applicationlevel protocol using UDP, and adopts a method of uniform retransmission as its error recovery strategy and it also introduces an improved DAIMD (AIMD with decreasing increases) rate control algorithm based on bandwidth probe. It can improve the data transfer rate with a low resourcetaken of embedded client. As the experimental result shows, compared with UDT and FTP protocol implemented on embedded terminal, EMFTP data transfer rate is increased by 3% and 17% respectively, the embedded client CPU occupancy ratios are reduced by 50.3% and 42.3% separately, and memory usage reduced by 15% and 4%.

7 Markov Logic Networks with its application in Deduplication

ZHNG Yufang , HUANG Tao , AI Dongmei , XIONG Zhongyang , TANG Rongjun

2010, 33(8):36-41. DOI: 10.11835/j.issn.1000-582X.2010.08.007

[Abstract](2548) [HTML](0) [PDF 1.14 M](1326)

Abstract:
In order to solve the limitation that the traditional Deduplications are mostly used for a specific field and only address one aspect of a problem,a scheme based on Markov Logic Networks (MLNs)is proposed, which is a new Statistical Relational Learning (SRL) model. With its advantage of computing the probability distribution of worlds to serve for the inference, the Deduplication is formalized. Discriminative learning algorithm is adopted for Markov Logic Networks weights, MCSAT algorithm is adopted for inference. It shows how to capture the essential features of different aspects in Deduplication with a small number of predicate rules and also combines these rules together to compose all kinds of model. The experiment results prove that the method based on Markov Logic Networks not only covers the original FellegiSunter model, but also achieves a better result than the traditional methods based on Clustering Algorithms and Similarity Measures in Deduplication. It reveals that the Markov Logic Networks can play an important part in practical application.

8 Harmonic detection method analysis based on BP network

CHENG Peiyun , ZHNG Meng , FAN bo , Dong Tao

2010, 33(8):42-45. DOI: 10.11835/j.issn.1000-582X.2010.08.008

[Abstract](2095) [HTML](0) [PDF 1.28 M](1165)

Abstract:
A harmonic detect method based on BP network in power system is introduced.It resolves the problem learning of Hidden layer and can be used to detect power system harmonic.For the output of the Fourier form of BP network is equal with the Fourier series,the network is designed to be a SISI system.Hidden layer is composed with Fourier trigonometric functions as activation functions.Gradient descent is adopted to adjust weight.To ensure the convergence of the BP network,learning step η is set according to Lyapunov theorem.Simulation result shows that it improves the convergence speed and the precision of calculation.It acquires the harmonic magnitude and phrase precisely and quickly.

9 Analysis of reasonable wind farm energy storage capacity range

LU Jiping , ZHU Sanli , HAN Tao , LV Dong , LIU Lei

2010, 33(8):46-51. DOI: 10.11835/j.issn.1000-582X.2010.08.009

[Abstract](2794) [HTML](0) [PDF 1.95 M](1292)

Abstract:
The wind farm output power fluctuations caused by changing wind speed can be improved by configuring the appropriate storage energy capacity .For the problem that how to select the storage capacity more economical, two indicators for the judgment of the optimization wind power output are mentioned, which is based on a method calculating storage energy capacity. By detailed analysis of the all kinds of factors that can influence the reasonable value of storage capacity, and by using the cost of storage capacity and the smoothing effect of wind farm output as assistant criterion, a reasonable storage capacity range is discussed.

10 Cellular automata spatialtemporal data model and forecasting approach

REN Haijun , ZHANG Xiaoxing , ZHOU Quan

2010, 33(8):52-57. DOI: 10.11835/j.issn.1000-582X.2010.08.010

[Abstract](2795) [HTML](0) [PDF 1.98 M](1613)

Abstract:
The standard cellular automata(CA) model is expanded to meet requests of spacetime dynamic simulation and forecast under the platform of geographic information system(GIS). Taking power load forecasting of the electric power industry as the specific application, the relations between dynamic model of the land use and power load space are established. The data and attribute data interactive discrete in spatialtemporal data management have been solved. The CA theory is practically used to simulate the process of urban landuse dynamic development, to forecast future landuse types of each smallarea, to establish spatial load forecasting model. It breaks through the localization of all kinds of forecasting methods of traditional spacetime separation power prediction. The effectiveness of the prediction method is verified by example.

11 An improved rotorside control strategy of doublefedwind turbine generation system

HU Xueshong , SUN Caixin , LI Hui , ZHAO Meng , TANG Xianhu

2010, 33(8):58-63. DOI: 10.11835/j.issn.1000-582X.2010.08.011

[Abstract](2261) [HTML](0) [PDF 3.24 M](1218)

Abstract:
Based on a onsite wind turbine’s output activepower vs. generator speed curve, the shortage of conventional power control strategies of doublyfed wind turbine generation system are analyzed. Considering the generator speed restriction and activepower fasttrack control requirement, the power decoupling control strategy in the rotorside converter and variable pitch control strategy are improved, that is, an output mechanical torque of wind turbine and the generator speed of DFIG are used in the rotorside active power control loop in order to achieve an accurate optimal speed control, as well as a direct activepower control method is also adopted in the variable pitch control strategy. Finally, the overall operational performances of DFIG wind turbine generation system using the proposed control strategies are simulated, and also compared with the conventional control strategies. The results show that the improved control strategy is more valid and correct.

12 Electrocircuit principle’s research of ringspace array torque sensor’s reader head

YU Honglin , LI Rong , HE Anguo , Ma ShengtAo , WU Yongfeng

2010, 33(8):64-68. DOI: 10.11835/j.issn.1000-582X.2010.08.012

[Abstract](2527) [HTML](0) [PDF 1.86 M](1045)

Abstract:
Based on the principle of electromagnetic induction of exchange and the measurement principle of the ringspace array torque which is related to the sphere symmetry, the measurement principle of a ringspace array torque sensor is discussed which is fit for measuring in extreme environment. The reader head electrocircuit is designed which is combined with the problems on measurement of mechanical torque in extreme environment. The experimentation is emulated and the preferably satisfied result is gained.

13 Development of the remote data supervisory system of the hybridelectric vehicle

YaNG Yalian , CAO Ziwei , QIN Datong

2010, 33(8):69-74. DOI: 10.11835/j.issn.1000-582X.2010.08.013

[Abstract](2380) [HTML](0) [PDF 1.10 M](1561)

Abstract:
Taking the hybrid electric vehicle as the investigation subject, this paper studies the remote data acquisition, supervisory control and redisplay system of the hybrid electric vehicle fault diagnosis. The system gathers the simulate CANBUS data through serial ports by the data acquisition device and send data to the remote webservers by the GPRS wireless communication module. For the demands and features, the paper makes the module selection and design the hardware of lower computer ,and the software on the host computer and lower computer. It takes several notebooks as the simulate vehicledate emission source to make an experiment, achieving the function of wireless data transfer, data acquisition, supervisory, redisplay for multi hybrid electric vehicles at the same time, and protocol setting up. Especially the function of wireless data transfer and protocol setting up, make a big progress on the common use and convenience of fault diagnosis system.

14 Stringtop fast measurement method of the more teeth and small modulus cycloidal gears

LI Chaoyang , CHEN bingkui , LIU Jingya

2010, 33(8):75-79. DOI: 10.11835/j.issn.1000-582X.2010.08.014

[Abstract](2907) [HTML](0) [PDF 801.18 K](1196)

Abstract:
According to the selfgeometric characteristics of the cycloidal gear, stringtop method, one kind of fast measurement method which fits to the cycloidal gears that own the characters of small modulus and more teeth, is put forword. The calculating formulas of the distance between the sting and the top of the cycloidal gears’ theoretical tooth surface are given，furthermore, the distance of the modified profile of the cycloidal gears under the conditions that moving distance, equal distance and rotating angle are also discussed. The calculating program is written, stingtop method of the cycloidal gear’s fast measurement software is developed, calculation and measurement example is given.

15 Simulation analysis of control strategy for electric power steering system

XU Zhongming , HU Kangbo , YU Feng , ZHANG Zhifei

2010, 33(8):80-84. DOI: 10.11835/j.issn.1000-582X.2010.08.015

[Abstract](2454) [HTML](0) [PDF 1.20 M](1164)

Abstract:
The mathematical model of the electric power steering (EPS) system is developed，and control strategy is designed by the way of frequency analysis using Bode diagram，on a basis of steering feel expression．A complete model used for analysis of automotive steering characteristic，with fourtire and threefreedom vehicle models is built．In order to meet optimal goals，including steering agility，returnability and steering effort requirements of drivers, the rule of controller parameter values under the condition of different speeds and steering torques is concluded through numerous simulation tests．

16 The change rule of driver’s pupil size under road lighting conditions

HU Yingkui , WENG Ji , LI Yi , CHEN Zhonglin , ZHNG Qingwen

2010, 33(8):85-90. DOI: 10.11835/j.issn.1000-582X.2010.08.016

[Abstract](2877) [HTML](0) [PDF 2.23 M](1122)

Abstract:
In order to study the rule of drivers’ pupil changing with luminance under road lighting condition,pupil area of 4 subjects under 13 lighting levels of high pressure sodium(HPS), metal halide(MH) and LED are measured, with reaction time test equipment for road lighting and iView X eye tracking system. The results indicate that the relationship between pupil area and background luminance is negative exponential function, pupil will shrink while luminance is increased, the shrink velocity of pupil will decrease while luminance’s increasing, and pupil area will tends to be constant when luminance reach some level. Under the three lighting sources used in the experiment, pupil area will fluctuate while the background luminance is between 0.7 cd/m2and 1.2 cd/m2.

17 Microscopical static properties of the confined fluids in nanometer tubes

LIU Junfang , LI Qin , LING Xinli

2010, 33(8):91-95. DOI: 10.11835/j.issn.1000-582X.2010.08.017

[Abstract](2201) [HTML](0) [PDF 1.87 M](1005)

Abstract:
The static properties of the confined in the nanometer cylinder tubes are investigated by molecular dynamics simulation. The modified LennardJones potential function is adopted to describe the interaction between fluidfluid and fluidsolid. In which, the introduced parameter α can be adjusted to change the wetting intensity between the fluids and solid solid wall. Furthermore, the microscopic properties of the fluids in the nanometer tube are characterized by the density distribution, the pair distribution function and the axial velocity distribution. The results show that the interaction strength of the atoms between the fluids and solid wall has a significant influence on the microscopic properties of the fluids as well changes the microscopic state in the different radial region and the motional properties of the atoms consisted of the fluids in the tube.

18 Experimental study of properties of slope protection through grass jetting on 3D geomat

XIAO Chengzhi , SUN Jiancheng , LIU Xiyuan , LIU Xiaopeng

2010, 33(8):96-102. DOI: 10.11835/j.issn.1000-582X.2010.08.018

[Abstract](2602) [HTML](0) [PDF 1.58 M](1238)

Abstract:
Based on ecological slope protection models by orthogonal tests, comparative experimental study of properties of slope protection through grass jetting on 3D geomat considered types of 3D geomat, density of grass seeds, types of soil and slope gradient are conducted under different rain intensity. The results show that the sequence of sensibilities for erosion modulus is density of grass seeds, slope gradient, types of soil and 3D geomat under the condition of simulating light rain, geomat can play a remarkable role to erosion modulus under the condition of simulating rainstorm, the erosion modulus for slope protection by grass jetting 3D geomat reduces 5 times than nonprotection natural slope. Equivalent cohesion of soilgrassgeomat compound decreases with the increase of depth, and curvilinear regression between equivalent cohesion and depth is cubic polynomial expression. Permeability coefficient of surface soil tends to increase with thicker geomat and bigger density of grassroots.

19 Testing and modeling studies on creep characters of supports for tunnel using nonlinear constitutive model

JIN Xioguang , LI Xiaohong

2010, 33(8):103-108. DOI: 10.11835/j.issn.1000-582X.2010.08.019

[Abstract](2609) [HTML](0) [PDF 1.26 M](1164)

Abstract:
Creep characters of tunnel supports structure is analyzed according to triaxial creep test of concrete specimen of deep tunnel supports structure adopting MTS815 hydraulic servo system. The creep parameters of nonlinear creep model are presented based oncreep curve. The finite element numerical model has been established considering tunnel construction process, creep characters of surrounding rock and support structure. The displacement characteristics, the effective stress and the maximum shear stress in different position in primary support and second lining are obtained through creep characters analysis of surrounding rock and supports structure. The features of displacement and stress dependent time of tunnel supports has visible difference comparing with discard creep effect and calculation displacement and practical monitoring results is basic concordance. The creep characters of surrounding rock and tunnel supports should be considered for deep tunnel.

20 Analysis of plastic flow characteristics based on bridge steel 16Mn ratcheting

XIANG Yangkai , MA Yangbing , ZHENG Yi , ZHOU Zhixiang

2010, 33(8):109-113. DOI: 10.11835/j.issn.1000-582X.2010.08.020

[Abstract](2189) [HTML](0) [PDF 2.03 M](991)

Abstract:
Abstract:The analysis of the plastic flow characteristics on the basis of the ratcheting experimental results for the bridge steel 16Mn are carried out by calculatig the plastic modulus H and the angle θ between the backstress rate deviator and the plastic flowdirection. The different mechanisms causing uniaxial andmultiaxial nonproportional ratchetting are illustrated, that is, the starting and evolution of uniaxial ratchetting is due to the different values of the plastic modulus H at the symmetric loading points with respect to the mean stress. On the other hand, the staring and evolution of multiaxial nonproportional ratcheting is driven by H and θ variations. The influence of loading history on ratchetting is the result of the influence of loading history on the angle θ.

21 Simulation and analysis of infilledwall cracks’ development by shrinkage using semidiscrete and whole type model

FU Jun , JIN Weiliang , YUE Zengguo

2010, 33(8):114-122. DOI: 10.11835/j.issn.1000-582X.2010.08.021

[Abstract](1833) [HTML](0) [PDF 2.95 M](983)

Abstract:
Abstract:For computational efficiency, numerical simulation analysis of cracks’ development by dry shrinkage effect has been carried out on a practical meeting twostorey and single span wallinfilled frame structure. FEM models are used as semidiscrete type and whole type.Different column rigidity, opening sizes, and connection rigidity are discribed with deformation, stress, crack development results. The crack morphology and width can be comparable with practice.Gravity and vertical loads should be considered in model. Shrinkage causes large deformation near openings. Different column rigidity, opening sizes and connection rigidity cause different crack development and deformation. The uniform construction detailing is not enough for all. Primary crack of nonconstructional detailing wallinfilled frame may happen at -5 ℃ equivalent temperature, and the ultimate crack width can exceed usage permission. At last wall crack width by dry shrinkage is assessed, and some proposals are given.

22 Effect of pH controlling method on energy consumption of CO2 desorption from rschsolvent

DU Min , ZHANG Li , FENG bo

2010, 33(8):123-129. DOI: 10.11835/j.issn.1000-582X.2010.08.022

[Abstract](2467) [HTML](0) [PDF 1006.70 K](1088)

Abstract:
Solvent absorption is one of the main commercial methods for CO2 capture. However, the process of solvent regeneration is energy intensive and constitutes the main cost in the whole process. The paper investigates the feasibility of a new method ,which is ,to control the pH value of solvent in reducing the energy consumption in solvent regeneration. Some Selected weak organic acids are added into typical solvents which are MEA, DEA and MDEA. It is found that the energy requirement for the release of CO2 is significantly reduced, which however is sensitive to the type of acid added. Meanwhile, CO2 releases faster as more amount of acids added. PH controlling method is thus potentially applicable in solvent technology.

23 Performance analysis and application of threefluid separate type heat pipe exchanger

SHI Chengming , WANG Yang , XU Canjun , CUI Wenzhi

2010, 33(8):130-135. DOI: 10.11835/j.issn.1000-582X.2010.08.023

[Abstract](2152) [HTML](0) [PDF 905.23 K](1018)

Abstract:
The temperature transfer matrix equations for threefluid separate type heat pipe heat exchangers with the same and different heat transfer area in each heat pipe row are obtained by establishing an analytical heat transfer model in the cocurrentor countercurrentflow mode. Using the temperature transfer matrix equations of exchanger with the each row heat transfer area is similar. The relationships of heat exchanger effectiveness θ1, θ2 with M, NTU, U, Δti are derived in the cocurrentor countercurrentflow mode. For the designing and checking calculation of the heat recovery device for the large hot blast stove in steel plant, the theoretical results can be used and it is proved correct in practical application.

24 Fabrication and thermal expansion properties of particle reinforced Al matrix composites

LUAN baifeng , PEI YINGfei , HUNG Tianlin , YE Qing , HUNG Gungjie , YNG Qin

2010, 33(8):135-142. DOI: 10.11835/j.issn.1000-582X.2010.08.024

[Abstract](2213) [HTML](0) [PDF 1.94 M](1139)

Abstract:
Aimed at electronic packaging application, the different types of particles of Al2O3, AlN and SiC which the mean size is about 4 μm are selected and three types of composites are fabricated by squeeze casting method with the particle volume fraction is 40%. The results show that the microstructure of composites is dense and free of pores with the particle distribute uniformly. The mean linear coefficient of thermal expansion (CTE) of composites ranges from 11.51×10-6~18.62×10-6/K and increases with increasing temperature. The measured coefficient of thermal expansion of SiCp/2024 is lower than that of AlNp/6061 and Al2O3p/2024. The measured CTE values of Al2O3p/2024 composites agreed well with Kerner’s model, the CTE of AlNp/6061 is closer to the prediction by ROM, and the CTE of SiCp/2024 varies from lower limit to upper limit of Shapery’s model.

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